Okay, at least the loading time is improved when TPM is disabled. As for the delay with TPM, I don't have a good solution now. The grub2 verifier is designed to load the whole file into memory and then measure the file content with TPM, and this would take a while for the additional memory allocation and file reading. Maybe we can do the check in verifier's open() and show some messages to notify the user about the possible delay.